Re: Presenting results of categorical data?

2001-08-15 Thread Donald Burrill
On 14 Aug 2001, Nolan Madson wrote: I have a data set of answers to questions on employee performance. The answers available are: Exceeded Expectations Met Expectations Did Not Meet Expectations The answers can be assigned weights [that is, scores -- DFB] of 3,2,1 (Exceeded, Met,

Re: Presenting results of categorical data?

2001-08-15 Thread Thom Baguley
Donald Burrill wrote: I agree on all of this. I'd add that at issue is whether people find the mean format useful, whether it is misleading. I'd use -1, 0 and +1, rather than 1-3. In this case the mean gives you at-a-glance summary of the extent to which the people who exceeded expectations

RE: Presenting results of categorical data?

2001-08-15 Thread Silvert, Henry
I would like to add that with this kind of data we use the median instead of the average. Henry M. Silvert Ph.D. Research Statistician The Conference Board 845 3rd. Avenue New York, NY 10022 Tel. No.: (212) 339-0438 Fax No.: (212) 836-3825 -Original Message- From: Donald Burrill

Re: Presenting results of categorical data?

2001-08-15 Thread Robert J. MacG. Dawson
Silvert, Henry wrote: I would like to add that with this kind of data [three-level ordinal] we use the median instead of the average. Might I suggest that *neither* is appropriate for most purposes? In many ways, three-level ordinal data is like dichotomous data - though there are a

Re: Presenting results of categorical data?

2001-08-15 Thread Jon Cryer
I do not see how (probabilistic) inference is appropriate here at all. I assume that _all_ employees are rated. There is no sampling, random or otherwise. Jon Cryer At 11:14 AM 8/15/01 -0300, you wrote: Silvert, Henry wrote: I would like to add that with this kind of data [three-level

Re: Presenting results of categorical data?

2001-08-15 Thread Robert J. MacG. Dawson
Jon Cryer wrote: I do not see how (probabilistic) inference is appropriate here at all. Oh, it never is (strictly), outside of a few industrial applications. Nobody ever took a random equal-probability sample from all turnips, all cancer patients, all batches of stainless steel, all

Categorical data Take 2

2001-08-15 Thread Melady Preece
The discussion of categorical data has got me thinking about a project I am about begin. The goal is to use a variety of individual predictors (IQ, previous work experience, education, personality) to develop a model to predict "success" after a vocational rehabilitation program for

RE: Categorical data Take 2

2001-08-15 Thread Paul R. Swank
If your going to use discriminant analysis you will need a lot of data and it does assume the predictors are multivariate normal. Generalized linear models would seem best, particularly in the event that you don't know if they are ordinal. You can do a multinomial followed by a cummulative logit

RE: Presenting results of categorical data?

2001-08-15 Thread Simon, Steve, PhD
Nolan Madson writes: I have a data set of answers to questions on employee performance. The answers available are: Exceeded Expectations Met Expectations Did Not Meet Expectations The answers can be assigned weights of 3,2,1 (Exceeded, Met, Did Not Meet). One of my colleagues says that it is

Re: Categorical data Take 2

2001-08-15 Thread Rich Ulrich
On 15 Aug 2001 09:57:27 -0700, [EMAIL PROTECTED] (Paul R. Swank) wrote: PRS If your going to use discriminant analysis you will need a lot of data and it does assume the predictors are multivariate normal. - well, logistic has to assume (almost) the same thing, almost as strongly, when it has

Re: forecast efficiency

2001-08-15 Thread Tom Reilly
Cristian, Let me set you straight. Whomever did you the disservice of teaching you the DW should be scolded. DW only measures 1 period lag. Box-Jenkins methodology uses the Autocorrelation function and partial correlation function to evaluate all lags. I suggest that you look for the

Re: Optimal bin size for fitting histogram to normal pdf?

2001-08-15 Thread Greg Heath
Date: Tue, 14 AUG 2001 16:27:11 +1000 From: Hong Ooi [EMAIL PROTECTED] On 13 Aug 2001 18:59:10 -0700, [EMAIL PROTECTED] (David Goldsmith) wrote: Aloha! I'm fitting theoretically normally distributed data, of widely differing sample sizes, to Gaussians by histograming it and then using an